PM mentions census troubles in US speech

Prime Minister Malcolm Turnbull has raised Australia's census debacle to call for new ways of talking about cyber security.

In a speech to the Centre for Strategic and International Studies in Washington DC, Mr Turnbull said Australia struggled with the meaning of the word "attack" after the denial of service incident that led to the census website being shut down on census night.

"If a nation state says that it has come under attack, the meaning, and therefore the act itself, is weighted with tremendous significance," he said.

"We need to be able to communicate an accurate level of significance."

The public needed to know that a denial of service was equivalent to having a bus block a driveway so a car couldn't get out, while a hack meant someone breaking into a garage and stealing the car, Mr Turnbull said.

"If we hear of an air disaster involving a cabin fire or an engine fire on an aircraft, we understand the difference between, and different implications of, those two scenarios," he said.